As the number of pixels of a photoelectric conversion element increases, a demand has arisen for aligning the light receiving surface of a photoelectric conversion element with respect to the image plane of an image sensing lens optical system at higher precision. To meet this demand, an image capturing apparatus needs to have a mechanism capable of adjusting the position (plane tilt) of a photoelectric conversion element with respect to the lens barrel.
The image capturing apparatus comprises a photoelectric conversion element, a driving circuit for driving it, and a signal processing circuit for processing a signal output from the photoelectric conversion element. The photoelectric conversion element needs to be electrically connected to a print circuit board on which the signal processing circuit and driving circuit are mounted.
As described above, the plane tilt of the photoelectric conversion element must be adjusted. Thus, the print circuit board which is attached to the image capturing apparatus main body and supports the signal processing circuit and driving circuit, and the photoelectric conversion element connected to the print circuit board need to be relatively movable.
For this purpose, according to the invention disclosed in Japanese Patent Laid-Open No. 11-261904, a photoelectric conversion element, and a print circuit board on which a signal processing circuit and driving circuit for the photoelectric conversion element are mounted, are connected by a flexible print circuit board. A position regulation member is arranged to regulate the position of a photoelectric conversion element package along the optical axis of a lens barrel. The position regulation member and the photoelectric conversion element package mounted on the flexible print circuit board are fixed. By finely adjusting the relative positions of the lens barrel and position regulation member along the optical axis, the light receiving surface of the photoelectric conversion element can be aligned at high precision with respect to the image plane of the image sensing lens optical system.
In the prior art, the photoelectric conversion element package is mounted on the flexible print circuit board, and the flexible print circuit board is extended and directly connected to the print circuit board on which the signal processing circuit and driving circuit are mounted. By using the flexible print circuit board for the connection, the photoelectric conversion element, and the print circuit board on which the signal processing circuit and driving circuit are mounted, are electrically connected to each other while they are relatively movable.
The interconnection from the photoelectric conversion element to the print circuit board on which the signal processing circuit and driving circuit are mounted, includes the signal output pattern of the photoelectric conversion element, and a driving pulse pattern for driving the photoelectric conversion element. The signal output pattern of the photoelectric conversion element is vulnerable to mixing of noise, and crosstalk from the driving pulse pattern must be prevented. Along with recent increases in the number of pixels of a photoelectric conversion element and the number of functions, the driving clock rate is increasing. An increase in unwanted radiation from the driving pulse pattern owing to the increase in driving clock rate must also be prevented.
To meet these requirements, according to the invention disclosed in Japanese Patent Laid-Open No. 9-298626, a slit is formed between the driving pulse pattern and signal output pattern of the flexible print circuit board on which the photoelectric conversion element is mounted. With this slit, the signal output pattern and driving signal pulse pattern are formed spatially apart from each other.
According to the invention disclosed in Japanese Patent Laid-Open No. 10-313178, a power supply layer and ground layer are arranged on inner layers. A driving pulse pattern and signal output pattern are arranged separately on two external layers so that they do not overlap each other when viewed from the top. This arrangement prevents interference of the driving pulse pattern with the signal output pattern.